The Application of Electrophoresis to the Study of Protein Variation

The application of electrophoresis to the study of protein variation in natural populations revealed that most organisms possess large amounts of genetic variation. The neutral-mutation hypothesis proposes that most molecular variation is neutral with regard to natural selection and is shaped largely by mutation and genetic drift. The balance hypothesis proposes that genetic variation is maintained by balancing selection.
-Which statement is true of the neutral-mutation hypothesis?

A) All proteins are functionless.
B) Natural selection plays no role in evolution.
C) Most molecular variants are functionally equivalent.
D) All of the above.